Over the years, a number of enzyme products have been developed for incorporation into detergents. Unfortunately, many commercially prepared enzyme-based products have certain drawbacks. Enzyme-based products are often difficult to handle, may cause an irritating dust, may be incompatible with other detergent ingredients, and may deteriorate in the presence of moisture. In addition, it is well known in the art that enzyme deactivation occurs in aqueous detergent compositions containing enzymes.
Consequently, there is a standing desire to prepare enzyme products suitable for detergents which overcome the above drawbacks.
It has now been found that one or more enzymes immobilized on an activated polymer are very suitable for incorporation into detergent compositions. The inclusion of such immobilized enzymes in a detergent composition provide an improved thermal stability, especially in liquid detergents. In addition, an improved resistance of said immobilized enzymes occurs against premature proteolysis due to protease. Furthermore, a better controlled enzymatic activity on fabrics can be achieved using said immobilized enzymes on an activated polymer in detergents.
In addition, it has been surprisingly found that utilization of said immobilized enzymes in detergents also delivers an important whiteness maintenance and a reduced potential to generate improved odor characteristics.
It is known in the art that enzymes can be attached to polymers. In Applied Microbiology and Biotechnology (1985), 21:37-41 is disclosed the immobilization of Aspergillus niger cellulase on cyanogen bromide activated dextran of varying molecular weights. In Enzyme Microb. Technology, 1983, Vol 5, 342-344 is disclosed the immobilization of three cellulase components of Penicillium funiculosum on a soluble, high molecular weight polymer (polyvinyl alcohol), using carbodiimide. In Prikladnaya Biokhimiya i Mikrobiologiya, Vol 14, No. 5, pp703-708 is described the covalent immobilization of lipase and amylase on soluble and insoluble copolymers of N-vinylpyrrolidone with glycidyl acrylate and glycidyl methacrylate. In the Japanese patent application J06240297 of Toray Industries is disclosed a cleaning agent containing enzymes immobilized on water-soluble organic high molecular weight polymers. The agent is prepared by mixing the enzymes and a polymer, preferably a methyl vinyl ether-maleic anhydride copolymer. Using this method the enzyme loosely immobilized on the polymer can easily be washed/rinsed away from the polymer.
However, nowhere is disclosed the benefit of using enzymes immobilized via a covalent binding on activated polymeric supports in detergent compositions.